6. define common sense

and yes, it is a political agenda. Part of the problem is simply getting local police to enforce existing federal law. Under federal law, he should have turned in or disposed of his guns. It is a federal crime to possess a gun.
Question, how would you enforce the requirement for a private sale being brokered by an FFL?

8. A lot of things are responsible for senseless deaths ...

... firearms being way behind things like bathtubs, swimming pools and automobiles -- none of which are Constitutionally Protected. But, I've yet to see either party's platform call for a ban on spas or jacuzzis.

And yes ... for the record ... Gun Control ("common-sense" or otherwise) is the textbook definition of a political agenda.

3. at the risk of being a precision nazi,

but it is the INTP in me.
The article reads:

He had bought the .40-caliber semiautomatic handgun he used in the attack from a private owner on Saturday, according to police in Brown Deer, the Milwaukee suburb where Haughton lived. The seller did nothing illegal; private individuals are not required to conduct background checks or enforce a 48-hour waiting period as licensed gun dealers are under state law.

How it should read:

He bought the .40 caliber semiautomatic handgun he used in the attack from a private owner on Saturday, according to police in Brown Deer, the Milwaukee suburb where Haughton lived. The seller did nothing illegal; private individuals are not allowed to conduct background checks as licensed gun dealers are required under federal law or enforce a 48-hour waiting period as licensed gun dealers are under state law.

It seems to me that the state does need to get its enforcement act together. How the state is going to get the city and county police to better enforce a federal law, I am not a police administration wonk.
BTW
http://www.democraticunderground.com/117281257